Flowers differ in many ways, and it is by observing their differences of form, colour, habit, and structure that we are able to arrange them in families and orders. If we look at the shapes of the blossoms we find some are like a bell and others like an insect. This one is round, or salver-shaped, and that is fashioned like a thimble. When we study the colours we observe that there is the same infinite variety. We have the peculiar yellow of the primrose (Fig. 1) and the scarlet of the pimpernel (55). The flaming colour of the poppy (Plate I) is opposed to the dazzling whiteness of the water lily (Plate II). We have large numbers of yellow, white, and blue flowers; but even greater numbers are marked with variations in patches, spots, lines, and patterns.
Plate III. - Deadly Nightshade.
Some plants creep, or send out suckers or stolons; while others have tendrils, hooks, and feelers, by means of which they climb and ramble. If we dig up specimens we observe that some have corms, tubers, and rhizomes, while others have scales or fibres. We are struck by the varying number of sepals and petals, of stamens and pistils, the solitary blossom here, the mass of flowers there. Some droop, others are erect; these are in broad umbels, those in spikes, tassels, clusters, or panicles. While the larger number of flowers open by day, some are most conspicuous at night, and many open and close at regular hours. The goat's-beard, pimpernel (55) or poor man's weather-glass, and evening campion are wellknown illustrations. We are struck by the fact that some plants are fleshy, others are dry. These have edible fruits; those have seeds, with down or wings, and others possess vessels which jerk their seeds from them.
Such matters as these it is of the first importance to study. Mere classification, while it enables us to identify a plant by means of its organs, teaches us little of its wonderful history, and the chief end of our study is to teach us this. As an aid and supplement to the following classification, we will now study some of the many points of structure.
The Blossom is usually the first thing to arrest our attention. We first note its colour. It may be all of one hue, as in the buttercup; or variegated, as in many of the orchids. The blossoms may be regular or irregular, with the sepals and petals separate or conjoined. Flowers which belong to one Natural Order (N.O.) are usually very much alike, although there are important exceptions. We find, for example, a great similarity between all the umbels (Group vi), the labiates or lip-flowers (Group iv), the orchids, the roses and buttercups, and other plants. But differences often exist. The columbine and monkshood (173) do not look much like buttercups, though they belong to the same family.
Fig. 8.- Bladderwort (Utricularia).
There are many plants among the rose family (Group xvii) which look very much like buttercups (Group xviii); but if we study the explanations attached to these two groups, we shall at once see how widely they differ. We ought here specially to note the following:
Composites (Group VIII). Example : Daisy. Plants whose flowers are compound. Each of the perfect flowers has five stamens, the anthers of which form a tube. See Horse Daisy, Fig. 19.
Labiates (Group IV). Example: Mint. Flowers lip-shaped, four stamens, and four seeds or nutlets in an open receptacle.
Legumes (Group XV). Example: Pea. Flowers butterfly-shaped, stamens ten, seeds usually in pods. A few plants, such as fumitory and the little blue milkwort, the butterwort and bladderwort, somewhat resemble labiates and legumes, as do also some of the Broomrapes and Scrophulariaceae (Group IV), Fig. 24.
Crucifers (Group x). Example: Wallflower. There are four petals and six stamens. They can easily be distinguished from other plants with six stamens (Group ix) by the number of petals and the shapes of the leaves (Fig. 22).
Umbels (Group VI). Example: Carrot. Flowers spreading like an umbrella, nearly always white.
In many instances the flowers take the form of tassels, some of which are regular catkins, while others only loosely resemble these. Many of our native trees bear genuine catkins, and may be easily recognized thereby. The catkins of hazel and birch appear in winter. Those of the willow are large, and are often called palms. The alder, poplar, sweet gale (21), and other shrubs and trees also bear them. In the oak they are loose, and are not unlike the tassels found in dog's mercury (115), nettle (17), and elsewhere.